File storing and sharing method

Abstract

The application discloses a file storing and sharing method. The file storing method comprises the following steps: splitting a file into a plurality of data blocks by a client side; calculating the content of each data block respectively through a Hash algorithm, and taking the obtained Hash values as content secret keys to encrypt the data blocks respectively to obtain a plurality of ciphertext data blocks; uploading the ciphertext data blocks to a storage server; encrypting the position of each ciphertext data block in the storage server, the position of each ciphertext data block in a source file and the content secret keys respectively through a mapping secret key to generate mapping information, encrypting the mapping secret key through a public key of a file possessor to generate secret key information, and transmitting the mapping information, the secret key information, the filename and the identification of the file possessor together to a metadata server. According to the file storing method disclosed by the application, file storing safety can be improved; during file sharing, the file can be shared only by setting different re-encrypting secret keys for authorized users, and the secret keys are not needed to be updated frequently.

Description

technical field [0001] This application relates to file storage and sharing methods. Background technique [0002] In order to improve data security and storage efficiency, files can be encrypted and stored and shared. Specifically, the client can obtain a hash value summary of the file and upload it to the server to determine whether the file to be stored already exists. Then only the location of the duplicate data block on the server and the key of the duplicate data block will be returned. If there is no duplicate, the encrypted file will be uploaded, and the encryption key will be uploaded to the server so that others who are not authorized but upload duplicates of the file will be uploaded. And deleted users can read it. [0003] However, in the above scheme, the keys need to be updated continuously for different authorization groups, and there are high trustworthy requirements for the server and its administrators, and the keys and content may be leaked to the server....

AI Technical Summary

Problems solved by technology

[0005] However, according to this scheme, it needs to be uploaded for comparison each time regardless of whether it is repeated or not. If the transmission volume is too large, bandwidth will be wasted and time-consuming; the metadata server needs to store more encrypted mapping keys, and it will be based on authorized increase in number of users

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